During the early morning, pre-dawn hours of All Hallow's Day, you were
visited by three spirits: the Ghosts of Halloween Past, Present and
Future.  They brought with them a ? bacteriophage that carried an
inversion of its DNA, flipping the region of DNA from between the CI
and the rex genes to between tR and cII, as shown below.  They also
brought four possible host strains to choose among for propagating
this bacteriophage.  They told you that you must grow up the
bacteriophage by Christmas, otherwise your soul would be forfeit.  You
must choose one of the four strains in order to grow the phage.  (It
seems new management, the Ghosts of Christmas Past, Present and
Future, starts work on Christmas; and all the soul-searching
bookkeeping must before the new management takes over.)  Although you
think this might all be a prank, you decide to solve the problem just
to be on the safe side.
      
http://biohelpme.blogspot.com/

On which of the four host strains below, if any, would this mutant
bacteriophage grow lytically or lysogenize?   Explain WHY or WHY NOT?

wild-type







hflA- (i.e. null mutant for hflA)







? lysogen







hflA- ?-lysogen  (double mutant)